Pollutant emission studies on aircraft propulsion systems have shown that pollutants are emitted in climatically highly sensitive regions of the atmosphere. Accordingly, attention has long been directed increasingly to pollutant reduction. Apart from the optimization potential of such major turbine engine components as the compressor, turbine and exhaust nozzle, it is the combustion chamber which still has considerable potential for reducing pollutants, especially nitrogen oxides, produced during combustion. Basically, there are three options to lower gas turbine pollutant emission: use an environmentally more beneficial fuel, lower the specific fuel consumption, and modify the combustion process. The first of these approaches requires a highly complex, novel fuel infrastructure, and reduction of fuel consumption is currently being tackled by optimizing the above-cited components. Attempts to modify the combustion process, finally, gave rise to two different concepts. In accordance with one of these concepts, known as the rich-burn lean-burn variation, the operating point in a primary combustion zone of the combustion chamber is shifted towards the rich-burn mixture, and a second lean-burn stage is arranged downstream of the primary rich-burn stage. Greater potential still for the reduction of nitrogen oxide emissions is the lean-burn concept, where the fuel is burned in a primary combustion zone with excess air. This places the combustion chamber operating point in a lean-mixture region with notably reduced pollutant formation. If nitrogen oxide formation is to be prevented, a homogenous combustion mixture is an essential requirement. With previously implemented combustion chamber concepts featuring separate rich-burn primary and secondary combustion zones, the fuel is injected directly--without premixing--into the primary combustion zone and is mixed thereat. It nevertheless runs the risk of igniting before the mixing process is complete. This locally produces so-called hot pockets of aggravated nitrogen oxide formation. In the prevaporizing lean-burn concept there is an added risk--if the flame does not stabilize sufficiently--of spontaneous ignition in the prevaporizer. This may damage, if not destroy, the combustion chamber.